Electrical commutator machine



Oct. 4, 19312. cs. GUERIN ELECTRICAL COMMUTATOR MACHINE Filed April 7,1950 [772/21 tor." b 69 F6 )"d urg 7 M% W Patented Oct. 4, 1932GERARBGUERI-N. onrnmsg-rmmcn ELncraIcAr. .commurn'ron. MACHINEApplication fil'i1pri1 '7f1930fSe'rial N6. 442,354, and. in France April13 11929 The present] invention has -foi '-itsix-obj e ct' a deviceforthe-improvementof the commutation'in electrical commutatormachines;*it'or continuous :or-'forralternatiiig current:

5 It 'is-known'that=the-diificulty-'of-commuta tion-sincreases inproportion to the-rate *of variationnof the "flux; which emanates fromeach tooth beside the slot in? which the section in course ofcommutation is located."

In "orderto improve the com-mutation,- it has already been proposed-"to" arrange in'- -the slots; together with ltlreuarmature winding, anauxiliary winding constituted by short circuited sections which slowdown the variw; ation of the flux emanating from the teeth duringcommutation. But these windings are the seat of considerableelectromotive forces during their passage under the main poles and thecirculating currents which are set 2011 up produce considerable heatingof the armature, especially in powerful machines, which forbids the useof such windings.

The present invention provides a notable improvement in this knowndevice by supzligpressing completely the circulating currents due to theaction of the main poles.

It consists in the fact that the closed circuits employed have the shapeof a figure 8, of which the loops each surround one half aorof thelength of a tooth, and in that the surface area of each loop ispenetrated by an equal flux emanating from the field magnet such thatthe electromotive forces induced by the flux emanating from the fieldmagnet shave an aggregate value of nil, and that on the contrary theelectromotive forces induced by the reverse flux during commutation areadded together.

The accompanying drawing represents by Oriway of example two forms ofcarrying out the invention.

Fig. 1 is a developed view of a part of the rotor of a commutatormachine having an arrangement of the windings according into theinvention;

Fig. 2 is a developed view illustrating a modification of the inventiondiscussed in Fig. 1.

In the form of construction indicated in boifFigure 1, the teeth D D D Dand the slots of the armature are inclined-{while the mass oiiarmaturelaminatiohs is 'subdivided into two equal parts by a ventilatingchannel" V; the auxiliary short-circuited winding is formed by aconductor 3 A; simply insulated 55 and twisted in the shapeof a figure8, whi'ch 3 embraces atx'oneend the half-toothD in oneedii'ection-and atthe 'other'en'd'thef ha'lf f t0oth"D -in the contrary direction: The" incli-iiation of the-slots issuchthat the half; tooth D andthehalf-tooth'D are" at each F instant under the-same edge the: pole P;

assumed to be straight; so that they arefswept' at-each'instant by thesame'flux: The electrom otive force induced in the S-shaped aux iliary"damping winding A is" thus ni'l for section B "of the mainwinding,'whichiscom. tained in the-slot outlined byfitheteeth D D andD51); is under commutation, the Variation of theflux' en'lanating rfrom'the tooth DiDf is in the contrary direction'rto that which {emanatesfrom :the tooth D5 Dg and the electromotive forces induced in' the twoloops of the auxiliary sshapefd winding are added together "to "create a'hifgh'fdahlping, current.- I p It isclear tliat'inst-ead of incliningthe teeth "of the armature, the pole tips. on the stator can beinclined:

In the form of construction represented in Figure 2,a stepped shape i'sad'apted for the sides of the section of'the main Windingandthestr'aight figm'eOfthe 'Q "shape for the sectionsof the auxiliarydamping winding. These sections each embrace-two" half-teeth of the:armature" whi'ch' are in line with" one anothcr." Theicrossingof theconductors ofthe auxiliary winding is effected in thelventil latingchannel V; while? the main. conductor section B passesifrom a slot Citoa slot C ofl-I set-to th e'extent of one toothfl It will bese'enatjonce that the 'electromoti've forces, indu'cedbytlievariatioirof theflux due tothe 95 commutation-fare added together and createa highdamping current, whilefthe electromotive forces induced 'by the 'fluX"emanating from the pole tips, '-assu'med' td'be" straight," neutralizeoneanother and create no current." 100 In the preceding arrangements,the auxiliary damping winding is not the seat of any induced currentduring the passage of the teeth under the main or the auxiliary poles Pof the machine. V

The invention is evidently not limited to the arrangements described,and it can be carried out according to different modifications. Inparticular, the auxiliary winding may be composed of plain open loops ofwhich the extremities are connected to the bars of an auxiliarycommutator, the brushes of this commutator short circuiting the loopsduring their passage under the commutating pole tips.

What I claim is: v V

1. Anelectrical commutator machine, comprising a field magnet, anarmature, teeth provided at the periphery of said armature and dividedin equal parts by transverse channels, main windings arranged in theslots of the armature in combination with auxiliary short circuitedwindings arranged in said slots and said transverse channels, each ofsaid auxiliary windings havin the shape of a figure 8, the'half loop the8 surrounding different parts of equal sections of the teeth, the partsof the main winding conductors located in the slot being adjacent to theopposite sides of each of the two half loops of the auxiliary winding,so that the halves of each loop of the auxiliary winding are subjectedto identical field conditions when they pass under the pole pieces, andthat the electromotive forces hereby induced in the two half loops areof opposite senses and compensate each other, while the E. M. F. inducedin the said half loops by the reversed flux during the commutation inthe main winding, are of the same sense and are added together.

, 2. An electrical commutator machine comprising a field ma'gnet,anarmature,teeth provided at the periphery of said armature and arrangedat an angle to the axis of the armature, said teeth being divided in twoequal parts by a transverse channel, a main winding arranged in theslots of the armature, in combination with auxiliary short circuitedwindings arranged in said slots and said transverse channel, each ofsaid auxiliary windings having the shape of a figure 8 the two halfloops of which are staggered and surround opposite halves of twoadjacent teeth of the armature, a part of each conductor of the mainwinding being located in the same slot adjacent to the opposite sides ofthe two halves of each loop of the auxiliary winding, so that the halvesof each loop of the auxiliary winding are subjected to identical fieldconditions when they pass under the pole pieces and that the E. M. F.hereby induced in the two half loops'are of the contrary sense andcompensate each other,

while those induced by the reversed flux durthe electromotive forces,induced ing the commutation of the main winding are of the same senseand are added together.

3. An electrical commutator machine, comprising a field magnet, anarmature, teeth provided at the periphery of said armature parallel tothe axis of the poles of the field magnet, said teeth being divided intwo equal parts by a transverse channel, main windings arranged in theslots of said armature, each of said windings being located partly inone slot and partly in the opposite half of an adjacent slot, incombination with auxiliary short-circuited windings, arranged in saidslots and in said transverse channel, each of the said auxiliarywindings having the shape of a figure 8, of which the loops surround theopposite halves of the same tooth of the armature, the relativedirection of winding of these two loops bein such that from the fieldmagnet, have an aggregate value of nil, while those induced by thereverse fluxduring commutation are added together.

In testimony whereof I have signed my name to this specification.

GERARD GUERIN.

